Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that there's a problem with the fuel injector for cylinder 4 in your car. It's like a tiny hose that sprays fuel into the engine, and it's not working right because of an electrical issue.
The P3157 code indicates an electrical issue where the high side of the high-pressure injector for cylinder 4 is shorted to the coil, causing improper injector operation.
The high-pressure fuel injector for cylinder 4 is experiencing a short circuit condition where the high side of the injector is making contact with the coil circuit. This can lead to improper fuel delivery and engine performance issues.
• Engine misfire
• Poor fuel economy
• Check Engine Light illumination
• Damaged wiring or connectors
• Faulty injector
• ECU malfunction
Injector: A device that sprays fuel into the engine's cylinders.
ECU: Engine Control Unit, the computer that controls engine functions.
• Inspect the wiring and connectors for damage or corrosion.
• Test the injector resistance and check for shorts.
• Scan the ECU for additional codes or malfunctions.
• Repair or replace damaged wiring/connectors.
• Replace the faulty injector.
• Reprogram or replace the ECU if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$200 - $600
Moderate
• Toyota Camry
• Honda Accord
• Ford F-150
• Regular maintenance checks
• Ensure proper electrical connections
• Use quality fuel
Engine Performance
• Have your vehicle inspected by a professional.
• Avoid driving long distances until the issue is resolved.
Check with your vehicle manufacturer; powertrain warranties may cover injector issues.
This code has been associated with injector and wiring issues in various vehicle models.
Moderate – It should be addressed soon to avoid further engine performance issues.
Ignoring this code may lead to increased emissions and potential engine damage.
• Engine running
• Warm engine temperature
The high-pressure injector for cylinder 4 is located on the engine, typically near the intake manifold.
Q: What happens if I ignore this code?
A: Ignoring this code can lead to poor engine performance and increased fuel consumption.
Q: Can I drive my car with this code?
A: It's not recommended to drive for long periods with this code, as it can cause further engine issues.
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Network faults often require full-system access instead of a generic code reader alone.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.